1. Field of the Invention
This invention relates to a method of assembling parts to a vehicle body and a self-running carriage for carrying a vehicle body on a vehicle assembly line.
2. Description of Related Art
In a typical vehicle assembly line, a fundamental work, such as a chassis frame and an engine to which various parts are assembled, is carried by a self-running carriage along the vehicle assembly line. A plurality of robots, installed along both sides of the vehicle assembly line, perform assembling, such as bolting, riveting and welding, of various parts to the chassis frame placed on the self-running carriage. The parts to be assembled to the chassis frame are collectively stacked on a parts-pallet in close proximity of each robot. A large number of parts-pallets are required, as many as the number of types of parts, and a considerably large space is required in order to arrange these parts-pallets.
In recent years, many different models of vehicles are simultaneously assembled on the same vehicle assembly line. Accordingly, parts, which are different for different models of vehicles, must be placed on separate parts pallets which require even a greater space for disposition. This has resulted in a mass of confusion on both sides of the vehicle assembly line and the difficulty of management of the large number of parts-pallets.
In the automobile assembly line wherein different models of vehicles are jointly assembled, in order to make self-running carriages available to different types of fundamental works, such as chassis frames and engines, from the economic viewpoint, a self-running carriage is provided fitted with a plurality of support stands, three dimensional positions, which are adjustable so as to support portions of fundamental works which are different according to the models of the vehicles being assembled. Conventionally, the adjustment of three dimensional positions of the support stands are accomplished by means of actuators mounted on the self-running carriage. This results in an undesirable increase in the size of the self-running carriage.